# Copyright 2022 The TensorFlow Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
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"""Flags related to distributed execution."""

from absl import flags
import tensorflow as tf

from ._conventions import help_wrap


def define_distribution(worker_hosts=True, task_index=True):
    """Register distributed execution flags.

  Args:
    worker_hosts: Create a flag for specifying comma-separated list of workers.
    task_index: Create a flag for specifying index of task.

  Returns:
    A list of flags for core.py to marks as key flags.
  """
    key_flags = []

    if worker_hosts:
        flags.DEFINE_string(
            name='worker_hosts',
            default=None,
            help=help_wrap(
                'Comma-separated list of worker ip:port pairs for running '
                'multi-worker models with DistributionStrategy.  The user would '
                'start the program on each host with identical value for this '
                'flag.'))

    if task_index:
        flags.DEFINE_integer(
            name='task_index',
            default=-1,
            help=help_wrap('If multi-worker training, the task_index of this '
                           'worker.'))

    return key_flags
